Femtosecond laser filamentation see leang chin springer. Applications expertise glass processing, clearshape. It is shown that the introduction of a thin plasma string created by another femtosecond pulse, perpendicularly to the filaments path, dramatically reshapes the thirdharmonic beam into a bessellike farfield distribution, while at the same. The filament formation and output spectrum changed very sensitively to the initial laser. To calculate the filament wandering in air we have developed a model of powerful femtosecond laser pulse filamentation. Laser chirp effect on femtosecond laser filamentation. The coexistence of filamentation and breakdown is observed under tight focusing conditions. Space based femtosecond laser f ilamentation final report authors.
From selffocusing light beams to femtosecond laser pulse. Optimization of multiple filamentation of femtosecond laser pulses in air using a pinhole. Filamentation of femtosecond laser pulses in turbulent air. Femtosecond laser filamentation filamentation denotes a peculiar phenomenon related to the propagation of a beam of light through a medium without apparent diffraction.
Pdf femtosecond laser filamentation in condensed media. Filamentation of femtosecond laser pulses in turbulent air 1 center for optics, photonics and lasers, department of physics, laval uni versity, quebec, g1k 7p4. Laser filamentation of a femtosecond pulse in air at 400nm t. Highintensity femtosecond pulses of laser light can undergo cycles of. Recent developments in femtosecond filamentation iopscience. Facebook linkedin twitter youtube contact jove recommend jove. Pdf conical forward thz emission from femtosecondlaser. Insitu visualization of multiple filament competition dynamic during. Counteracting the natural spreading of the beam is possible with intense laser pulses owing to the optical kerr effect, which causes a change of the refraction index in the. Femtosecond laser pulse filamentation versus optical. Filamentation formed by selffocusing of intense laser pulses propagating in air is investigated. Femtosecond filamentation in transparent media sciencedirect. By launching an infrared pulse with femtosecond pulse over critical power p c r 3.
Spacebased femtosecond laser filamentation arianda fp. Simulation of selffocusing of femtosecond laser pulses in. Sapphire laser in air under selffocusing and filamentation are presented. Femtosecond laser filaments for use in subdiffractionlimited. Osa filamentation in air with ultrashort midinfrared pulses. The selffocusing of laser pulses is analyzed on the basis of the method of diffractionbeam tubes. Citeseerx document details isaac councill, lee giles, pradeep teregowda. Light filamentation produced by the femtosecond fs laser has aroused great interest since it was discovered for the first time in 1995. Springer series on atomic, optical, and plasma physics book 55 thanks for sharing. High peak powers of femtosecond laser pulses with pulse widths of less than 50 fs are commercially available and can be made to be relatively. We also show that this technique offers possibilities for steering. We show experimentally that an embarked terawatt femtosecond laser can significantly decrease this drag.
We measured a 50% transient reduction of drag on a test model placed in a supersonic wind tunnel at mach 3. Filamentation of ultrashort laser pulse train in air. This book attempts to give a discussion of the physics and current and potential applications of the selffocusing of an intense femtosecond laser pulse in a tra. Use a lens to couple the light from filamentation impact point into a spectrometer.
We have investigated the filamentation and selfcompression of femtosecond laser pulses in different optical media such as argon gas and fused silica by employing a model developed in the frequency domain. It is with great pleasure we invite you at the 3rd international symposium on filamentation cofil 2010 which will be held in crete, greece, in june 2010. When a flying object becomes supersonic, a concomitant increase in drag leads to a considerable rise in fuel consumption. Copy citation download citations reprints and permissions. Pdf filamentation of femtosecond laser pulses as a. Surf around, find the information you are looking for and enjoy. Femtosecond laser filamentation for atmospheric sensing mdpi. In this technical report, we will show the results obtained using stateoftheart numerical models developed during the ariadna study spacebased femtosecond laser filamentation, which was. Polarizationdependent femtosecond laser filamentation in air. Femtosecond laser filamentation ebook by see leang chin. First, the selffocusing of ultrashort laser pulses creates a plasma of lees 6. The influence of laser chirp on the formation of femtosecond laser filamentation in ar was investigated for the generation of fewcycle highpower laser pulses. The analysis established that specific light structures were formed in a laser beam during selffocusing.
Quantitative measurements of the properties of laser filaments at 400nm are presented. In particular, a theoretical and numerical model of the downward vertical propagation of intense femtosecond laser pulses launched from an orbital altitude of 400km was developed. During the past two decades, propagation of femtosecond laser pulse has attracted great attention both experimentally and theoretically. The combination of femtosecond laser filament ablation and emission spectroscopy is a potential analytical tool for standoff characterization of samples of interest. Tuning the size of gold nanoparticles produced by multiple. Mourou, selfchanneling of highpeakpower femtosecond laser pulses in. Nonlinear propagation of intense femtosecond laser pulses in bulk transparent media leads to a. The setup comprised a source of femtosecond pulses based on a. Studies of femtosecond pulse filamentation in glasses. Improving supersonic flights with femtosecond laser filamentation. The competition between femtosecond laser pulse induced optical breakdown and femtosecond laser pulse filamentation in condensed matter is studied both experimentally and numerically using water as an example. Results of numerical simulation of selfaction in air of a sequence of ultrashort laser pulses with a carrier in the near and midir regions are presented. The sc generation during filamentation of femtosecond laser pulses of different wavelengths in fused silica was studied experimentally using a femtosecond laser complex of the centre of collective using at the institute of spectroscopy. Supercontinuum generation by cofilamentation of two color.
These variations were used to compute the energy deposited in the flow by the laser filament see the supplementary materials. This effect was initiated by the thin hot air column created in front of the supersonic object by filamentation of the laser pulse. Improving supersonic flights with femtosecond laser. Control of femtosecond multifilamentation in glass by. Filamentation and selfcompression of femtosecond laser.
Polarizationdependent femtosecond laser filamentation in air article pdf available in chinese optics letters 167. Richard wagner, martin lepage, and daniel houde filamentation of femtosecond. Filamentation of intense femtosecond laser pulses in transparent dielectric media is a universal nonlinear. Filamentation of femtosecond laser pulses with amplitude modulation of a diffractionfree beam. Lasea presents for the first time it new micromachining workstation which is capable of very high precision machining like femtosecond laser cutting, drilling, engraving. Highly efficient broadband terahertz generation from. Femtosecond laser filamentation in condensed media with bessel beams.
Using fluorescence measurement and acoustic diagnostics simultaneously, filamentation and multiple refocusing of laser pulses were observed. It is found that the position of filamentation can be controlled continuously by changing the laser power and divergence angle of the laser beam. Femtosecond laser filamentation in gaseous media selffocusing. The main thrust is toward the development of efficient. Figure 5 demonstrates that saturation of the luminescence occurs over the range of laser intensities of 1. Excitation occurs on the order of several picoseconds, so that. The condition for the formation of a single filament has been carefully examined using 28fs laser pulses with energy over 3 mj. Control of filamentation induced by femtosecond laser. When a highpower, ultrashort midinfrared laser beam centered at 3. Femtosecond laser filamentation with different atmospheric. The process of thirdharmonic generation during the filamentation of intense ir femtosecond laser pulses in air is investigated experimentally.
The cofil 2010 is the third of a very successful series of conferences organized every 2 years. Precision laser glass cutting technology without any contour shape limitations. Selffocusing occurs when the phase shift due to kerr effect compensates for the phase shift. The properties of femtosecond filaments and their applications are presented. We theoretically investigate filamentation of ultrashort laser pulses in air in the midinfrared regime under conditions in which the groupvelocity dispersion gvd is anomalous. For short pulses of a few tenths of a femtosecond, optical field ionization is the dominating process for plasma generation in the filament. Filamentation of femtosecond laser pulses as a source for. Multiple refocusing of intense femtosecond laser pulses in air was studied both experimentally and numerically. Filamentation of femtosecond laser pulses with amplitude.
Generation and application of energetic, broadband terahertz pulses bandwidth 0. Selfcompression of optical laser pulses by filamentation. Results of the theoretical study of the propagation of femtosecond pulses of a ti. This project studied femtosecond laser filamentation from orbital altitudes. Ultrafast laser filamentinduced fluorescence spectroscopy. We compare the emission features and physical conditions of plasmas generated from metal targets using either by loosely focused femtosecond filaments or by lensfree filaments. A peculiar propagation of intense femtosecond laser pulses is observed in air without apparent diffraction or dispersion, during which the pulse is severely reshaped in the spatial, temporal and spectral domains 4. A contact acoustic monitoring technique was employed to perform spatiallyresolved in situ detection of microplasma formation and filamentation of focused femtosecond laser. Lasea femtosecond laser cutting and engraving youtube. In the present study, we consider the selfregulated generation of spatially homogeneous low density plasma ldp microchannels as a high intensity ionization source arising from the multi filamentation of powerful femtosecond fs laser pulses in aqueous solutions. Laser filamentation of a femtosecond pulse in air at 400nm. Formation and wandering of filaments in air are studied both experimentally and numerically.
617 893 1492 855 494 1575 1052 479 1323 303 1517 832 1067 887 1134 1306 1085 1494 546 949 962 1462 1384 296 853 600 228 18 832 1162 1262 978 917 1381 1396 419